Re: [time-nuts] need help with LPF
Hi NPO dielectric caps are not inherently microphonic. They only pick up audio / vibration if they are cracked or are placed under a lot of strain. At the roughly a micro henry range, a powdered iron core coil is the thing to use I would try for a single layer coil. Powdered iron is not microphonic. Windings can be if they are loose. Coils have the same issue as caps if they are cracked. Since they have a field, stuff moving close to them can be a very real issue. If you have a question about a part the normal thing to do is to first swap it out and next to burry it in potting compound. Hot wax is the old school thing to use. It doesn't take much to stop a part from wobbling around. If it's a field issue, copper foil and wax is the traditional debug approach. You mention three caps and one coil. Is one cap across the coil? How wide is the resonance? Lots of fun. Bob On Apr 12, 2010, at 9:10 PM, saidj...@aol.com wrote: > Hi Joe/Bob, > > the board is mounted extremely rigidly into the enclosure, so I don't think > it's flexing. But even if there were flexing I wonder what components > would give the best results. I am also sure the caps are COG as specified, > this > is from a small proto-run. Low values anyway (47pF etc). > > The vibration amplitude is less than 3g rms. The noise increases from less > than -145 at 1KHz under vibration to more than -120dBc due to the > resonance. > > If I bypass the passive filter the problem goes away. The passive filter is > very simple, three COG caps, one inductor. This is why I suspect the > inductor. > > Testing this at much less than -120dBc at 1KHz is not easy, since I need a > phase noise analyzer that takes more than 30 seconds to give results for a > measurement. So tapping with a hammer etc won't work. > > But I will try using my 8561E spectrum analyzer, maybe that will pick up > the tapping noise?! I think we are close to the noise floor of that SA. > > Maybe I could use a mixer and feed the audio output into an audio amp to > see if I can hear the tapping noise. But at -120dBc I need massive > amplification to hear anything... > > I like the idea of using leaded parts, since the leads will act as dampers. > Now if those parts will stay on the PCB during shock testing.. > > bye, > Said > > > > > In a message dated 4/12/2010 17:14:22 Pacific Daylight Time, > gw...@raytheon.com writes: > >> We are using a ceramic 560nH 0603 inductor, and believe that >> this part is picking up lots of noise around 500Hz to 1KHz when on the >> vibration table. Makes the Phase Noise of the Oscillator more >> than 20dB higher than without it! > > What is the vibration amplitude? > > I would guess that the inductor has a ferrite core, and that the ferrite > is magnetostrictive. > > High-K ceramic bypass capacitors are usually piezoelectric. > > SMD components pick up more strain from board flexing than other kinds of > component. Something with flexible leads may be less sensitive to > vibration. > > If you unsolder and remove the inductor, what happens? > > More generally, why are you suspicious of this inductor, versus 50 other > components? > > >> The caps used in the filter are small COG types, so I don't >> think they are the ones causing the microphonic sensitivity. > > I would try tapping the components with a plastic stick hit by a small > hammer while watching. > > >> I am thinking that a wire-wound inductor fully encased in epoxy >> would work better. > > Only if well shielded, to prevent EMI problems. > > It may work better simply because the leads are more flexible. > > > Joe > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Very unique clock
Hi Very cool indeed. I wonder how he got all the colors right with normal LED's? - The next generation of the clock will have microscopically small markings in a slightly Asian looking font on it.. They will randomly come up backwards and upside down to encourage one to learn to read modern resistors without rotating the board :) Bob On Apr 13, 2010, at 12:41 AM, Joseph Gray wrote: > http://hackaday.com/2010/01/15/know-your-resistors-tell-the-time/ > > I know I won't be the only one here who thinks this is very cool :-) > > Joe Gray > KA5ZEC > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Very unique clock
Yes, I wonder how it looks at 08:18 Chris -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: 13 April 2010 12:06 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Very unique clock Hi Very cool indeed. I wonder how he got all the colors right with normal LED's? - The next generation of the clock will have microscopically small markings in a slightly Asian looking font on it.. They will randomly come up backwards and upside down to encourage one to learn to read modern resistors without rotating the board :) Bob On Apr 13, 2010, at 12:41 AM, Joseph Gray wrote: > http://hackaday.com/2010/01/15/know-your-resistors-tell-the-time/ > > I know I won't be the only one here who thinks this is very cool :-) > > Joe Gray > KA5ZEC > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Very unique clock
In message <00f401cadb08$e0ed9b90$a2c8d2...@com>, "Chris Stake" writes: >Very cool indeed. I wonder how he got all the colors right with normal >LED's? A R+G+B LED combination has a pretty darn good color gammut these days, way better than most televisions (which is why the industry is howling madly at OLED btw. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Microphonic Inductor?
Said, I assume you are using something like the Coilcraft 0603 LS series which seem to have ferrite cores. You might want to try a 0805 size part since that inductance is available in the CS series which are ceramic only. I don't know if size constraints prohibit using an 0805 but you can try one to see if the inductor is the problem.If you must use a 0603, you might try massaging the filter impedance so you can use a 390 nH which is available in 0603 size with a ceramic core. Then, you will either have to put up with a mismatch or include some impedance matching components. I use the LS series 0603s a lot and they are somewhat temperature sensitive if that could be an issue. The ceramic cored CS series don't seem to be temperature sensitive. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid
In the name of drug enforcement, Texas is completely stopping anyone interested in science. I guess I was wrong in thinking Texas was different from the nanny states on the coasts. The US is molding its kids into good football fans and Walmart clerks. FWIW, -John = > Chems might be legal in Texas, but god forbid you have a flask without a > permit: > > http://www.statutes.legis.state.tx.us/Docs/HS/htm/HS.481.htm > > On Mon, Apr 12, 2010 at 5:40 PM, Bill wrote: >> Paul, do you live in Colorado or California? Most places in Texas >> where >> chemicals are sold carry this kind of merchandize and one is free to buy >> them...In quantity you may raise eyebrows but Texas is still a free >> country! >> >> -Original Message- >> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On >> Behalf Of paul swed >> Sent: Monday, April 12, 2010 5:14 PM >> To: Discussion of precise time and frequency measurement >> Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric >> acid >> >> Thats some serious stuff. >> I know a long time ago 30+ years you could buy all sorts of things for >> the >> amateur chemist. >> Especially if you lived in a farm region. >> Its funny how things have changed. Everything is so dangerous these >> days. >> I will say I needed sulphuric acid for a large battery set and after a >> big >> run around I did finally find a auto store that sold a gallon for $2.50. >> Three X more then I needed but what the heck. >> But my goodness what type of store are you talking about. Thats some >> serious >> stuff depending on the concentration. >> Regards >> >> On Mon, Apr 12, 2010 at 12:20 PM, Bill wrote: >> >>> I purchase 75% phosphoric acid at a commercial chemical >>> establishment...They >>> sell house cleaning chemicals for commercial cleaning folks. They sell >>> sodium hydroxide (caustic soda) outstanding for etching aluminum >>> outside a >>> closed space, nitric acid, sulphuric acid, hydrochloric acid, mek >>> (methyl >>> ethyl keytone), trichloroethylene (I think thats correct spelling), >>> etcphosphoric will burn your hands but even at 75% it is not that >>> caustic and putting hands in it momentarily to remove the object youre >>> cleaning is NOT that bad with a little cold water hand rinse (and >>> moisturizing crème as one weeney suggested), the damage is minimal >>> and >>> not >>> generally lasting. Chemicals are easy to find especially in the city >>> and >>> buying them over the internet might get you an inquiry from your local >>> DEA >>> officer, Police department or sheriffs dept. I can state that with >>> some >>> degree of accuracy as I was an elected District/County attorney for >>> approximately 14 years in Texas and had a close relationship with the >>> authorities. >>> >>> >>> >>> W5STP >>> >>> >>> >>> -Original Message- >>> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On >>> Behalf Of paul swed >>> Sent: Monday, April 12, 2010 8:08 AM >>> To: Discussion of precise time and frequency measurement >>> Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric >>> acid >>> >>> >>> >>> Well 8 oz fits my bill pretty well. >>> >>> Granted not 85% but from what I read on the thread I don't need that >>> >>> strength. >>> >>> Did look for jasco and did not see it. But it would be easy to overlook >>> >>> frankly. >>> >>> So many weird products >>> >>> >>> >>> On Mon, Apr 12, 2010 at 1:50 AM, Charles P. Steinmetz < >>> >>> charles_steinm...@lavabit.com> wrote: >>> >>> >>> >>> > Joe wrote: >>> >>> > >>> >>> > Where do you get [liquid phosphoric acid]? >>> >>> >> >>> >>> > >>> >>> > I buy concentrated (85% solution) phosphoric acid by the gallon on >>> eBay. >>> >>> > There are several good chemical suppliers selling that and other >>> useful >>> >>> > things. I've had good results with these folks, among others >>> (although >> I >>> >>> > dearly wish they'd switch from FedEx Ground to UPS): >>> >>> > >>> >>> > 250404008386 >>> >>> > >>> >>> > Best regards, >>> >>> > >>> >>> > Charles >>> >>> > >>> >>> > >>> >>> > >>> >>> > >>> >>> > >>> >>> > >>> >>> > ___ >>> >>> > time-nuts mailing list -- time-nuts@febo.com >>> >>> > To unsubscribe, go to >>> >>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> >>> > and follow the instructions there. >>> >>> > >>> >>> ___ >>> >>> time-nuts mailing list -- time-nuts@febo.com >>> >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> >>> and follow the instructions there. >>> >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To u
Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid
"J. Forster" wrote: > In the name of drug enforcement, Texas is completely stopping anyone > interested in science. I guess I was wrong in thinking Texas was different > from the nanny states on the coasts. The US is molding its kids into good > football fans and Walmart clerks. No argument. BTW, you want fries with that? :-/ -ls- ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid
Yeah. I want fries with my fries. :=)) As a kid, doing real chemistry and physic was what made school fun. We had real labs too! With real glassware and real chemicals. I'd have been utterly bored stiff with what they are teaching now. -John > "J. Forster" wrote: >> In the name of drug enforcement, Texas is completely stopping anyone >> interested in science. I guess I was wrong in thinking Texas was >> different >> from the nanny states on the coasts. The US is molding its kids into >> good >> football fans and Walmart clerks. > > No argument. > > BTW, you want fries with that? > :-/ > -ls- ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid
As a kid in the later 50's we made all sorts of pipe bombs and other interesting things. Potassium Nitrate was available as Saltpeter in drugstores as was other stuff, like Glycerin and Potassium Permologate. Amazing, we had a fun time, and, no one was ever hurt. Today we would be deemed as "terrorists". We could even go into a gun store and buy shotgun shells to take apart just for the powder. Regards - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Tuesday, April 13, 2010 10:39 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid Yeah. I want fries with my fries. :=)) As a kid, doing real chemistry and physic was what made school fun. We had real labs too! With real glassware and real chemicals. I'd have been utterly bored stiff with what they are teaching now. -John > "J. Forster" wrote: >> In the name of drug enforcement, Texas is completely stopping anyone >> interested in science. I guess I was wrong in thinking Texas was >> different >> from the nanny states on the coasts. The US is molding its kids into >> good >> football fans and Walmart clerks. > > No argument. > > BTW, you want fries with that? > :-/ > -ls- ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid
As a kid in the later 50's we made all sorts of pipe bombs and other interesting things. Potassium Nitrate was available as Saltpeter in drugstores as was other stuff, like Glycerin and Potassium Permologate. Amazing, we had a fun time, and, no one was ever hurt. Today we would be deemed as "terrorists". We could even go into a gun store and buy shotgun shells to take apart just for the powder. Regards - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Tuesday, April 13, 2010 10:39 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid Yeah. I want fries with my fries. :=)) As a kid, doing real chemistry and physic was what made school fun. We had real labs too! With real glassware and real chemicals. I'd have been utterly bored stiff with what they are teaching now. -John ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] OT: Re Technology. Was Naval Jelly
In the '50s, WW II was not ancient history. We met people who had used weapons, explosives, and other things in war and knew the risks. The same is true, but in a much more limited way, after 'Nam. However, starting in the '60s, society regarded science as evil and it became political. More recently, science has been warped to support political agendas. In a related way, cars, radios, TVs, and computers have "matured" to the point that even technically competant individuals can no longer modify or even repair them. (They still don't know if the Toyota failures are hardware, software, or a mix.) We are all becomng hostages to the priesthood of so called "experts" in big government and the big corporations, and we really have little idea what is fact and what is politically motivated disinformation. FWIW, -John > As a kid in the later 50's we made all sorts of pipe bombs and other > interesting things. Potassium Nitrate was available as Saltpeter in > drugstores as was other stuff, like Glycerin and Potassium Permologate. > Amazing, we had a fun time, and, no one was ever hurt. Today we would be > deemed as "terrorists". We could even go into a gun store and buy shotgun > shells to take apart just for the powder. Regards - Mike > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 > > > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of J. Forster > Sent: Tuesday, April 13, 2010 10:39 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid > > Yeah. I want fries with my fries. :=)) > > As a kid, doing real chemistry and physic was what made school fun. We had > real labs too! With real glassware and real chemicals. > > I'd have been utterly bored stiff with what they are teaching now. > > -John > > > > >> "J. Forster" wrote: >>> In the name of drug enforcement, Texas is completely stopping anyone >>> interested in science. I guess I was wrong in thinking Texas was >>> different >>> from the nanny states on the coasts. The US is molding its kids into >>> good >>> football fans and Walmart clerks. >> >> No argument. >> >> BTW, you want fries with that? >> :-/ >> -ls- > > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Re Technology. Was Naval Jelly
Hi John: In my youth I made black powder from drug store ingredients and later bought it in metal cans. I think the relative cost of labor has changed greatly over time. For example it used to be that you could buy a new U.S. automotive head lamp (reflector type) for under a dollar and have it installed and aligned for not much more money. But today the lamp is still under a dollar but the installation and alignment is a small fortune. By contrast a Honda lamp bulb (reflector is part of car) costs about $10 and you can install it in less than a minute, no alignment required. The cost of the installed lamp is much lower for the Honda. In order to lower the selling price it's common practice for a manufacturer to buy custom ICs which reduce board area. But, being custom, there are no replacement parts so no repair. When you can buy a new DVD player for about $40 it's a throwaway product, not economical to repair even if you could get parts. The Toyota Prius under charges and under discharges it's battery (66% SOC & 33% SOC) to prolong it's life. The battery lasts three times longer, the customer pays three times as much for the battery. (I wonder if there's a hack to change the SOC limits?) Makes the warranty more impressive. Have Fun, Brooke Clarke http://www.PRC68.com J. Forster wrote: In the '50s, WW II was not ancient history. We met people who had used weapons, explosives, and other things in war and knew the risks. The same is true, but in a much more limited way, after 'Nam. However, starting in the '60s, society regarded science as evil and it became political. More recently, science has been warped to support political agendas. In a related way, cars, radios, TVs, and computers have "matured" to the point that even technically competant individuals can no longer modify or even repair them. (They still don't know if the Toyota failures are hardware, software, or a mix.) We are all becomng hostages to the priesthood of so called "experts" in big government and the big corporations, and we really have little idea what is fact and what is politically motivated disinformation. FWIW, -John As a kid in the later 50's we made all sorts of pipe bombs and other interesting things. Potassium Nitrate was available as Saltpeter in drugstores as was other stuff, like Glycerin and Potassium Permologate. Amazing, we had a fun time, and, no one was ever hurt. Today we would be deemed as "terrorists". We could even go into a gun store and buy shotgun shells to take apart just for the powder. Regards - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Tuesday, April 13, 2010 10:39 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid Yeah. I want fries with my fries. :=)) As a kid, doing real chemistry and physic was what made school fun. We had real labs too! With real glassware and real chemicals. I'd have been utterly bored stiff with what they are teaching now. -John "J. Forster" wrote: In the name of drug enforcement, Texas is completely stopping anyone interested in science. I guess I was wrong in thinking Texas was different from the nanny states on the coasts. The US is molding its kids into good football fans and Walmart clerks. No argument. BTW, you want fries with that? :-/ -ls- ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Very unique clock
If you read the comments, the color issue is discussed. Seems the only color that isn't quite right is brown. Joe Gray KA5ZEC On Tue, Apr 13, 2010 at 7:04 AM, Poul-Henning Kamp wrote: > In message <00f401cadb08$e0ed9b90$a2c8d2...@com>, "Chris Stake" writes: > >>Very cool indeed. I wonder how he got all the colors right with normal >>LED's? > > A R+G+B LED combination has a pretty darn good color gammut these days, > way better than most televisions (which is why the industry is howling > madly at OLED btw. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] need help with LPF
Said, time-nuts-boun...@febo.com wrote on 04/12/2010 09:10:36 PM: > From: > > saidj...@aol.com > > To: > > time-nuts@febo.com > > Date: > > 04/12/2010 09:13 PM > > Subject: > > Re: [time-nuts] need help with LPF > > Sent by: > > time-nuts-boun...@febo.com > > Hi Joe/Bob, > > the board is mounted extremely rigidly into the enclosure, so I don't think > it's flexing. But even if there were flexing I wonder what components > would give the best results. I am also sure the caps are COG > as specified, this is from a small proto-run. Low values anyway (47pF etc). > > The vibration amplitude is less than 3g rms. The noise increases from less > than -145 at 1KHz under vibration to more than -120dBc due to the > resonance. At 500 to 1000 Hz, 3 g amplitude, even a stiff board will flex a lot. The flexing need not be visible to be an issue. > If I bypass the passive filter the problem goes away. The passive filter is > very simple, three COG caps, one inductor. This is why I suspect the > inductor. Ahh. > Testing this at much less than -120dBc at 1KHz is not easy, > since I need a > phase noise analyzer that takes more than 30 seconds to give > results for a > measurement. So tapping with a hammer etc won't work. Use a doorbell buzzer touching the rod? (Be sure to shield the buzzer well - build it inside a closed metal box with feedthrough capacitors on the power leads.) What may also work is to turn the problem inside out: With the board on the shake table being vibrated, touch the suspected component with a handheld soft plastic rod while observing the effect on phase noise. > But I will try using my 8561E spectrum analyzer, maybe that will pick up > the tapping noise?! I think we are close to the noise floor of that SA. > > Maybe I could use a mixer and feed the audio output into an audio amp to > see if I can hear the tapping noise. But at -120dBc I need massive > amplification to hear anything... Someone else suggested using a SSB receiver, which sounds workable. > I like the idea of using leaded parts, since the leads will act as dampers. > Now if those parts will stay on the PCB during shock testing. The leads can be fairly stout, so long as they can bend and relieve the stress when the PCB flexes. The component can also be glued to the board with soft conformal coat material or a dab of silicon rubber adhesive. Joe > bye, > Said > > > > > In a message dated 4/12/2010 17:14:22 Pacific Daylight Time, > gw...@raytheon.com writes: > > > We are using a ceramic 560nH 0603 inductor, and believe that > > this part is picking up lots of noise around 500Hz to 1KHz > when on the > > vibration table. Makes the Phase Noise of the Oscillator more > > than 20dB higher than without it! > > What is the vibration amplitude? > > I would guess that the inductor has a ferrite core, and that > the ferrite > is magnetostrictive. > > High-K ceramic bypass capacitors are usually piezoelectric. > > SMD components pick up more strain from board flexing than > other kinds of > component. Something with flexible leads may be less sensitive to > vibration. > > If you unsolder and remove the inductor, what happens? > > More generally, why are you suspicious of this inductor, > versus 50 other > components? > > > > The caps used in the filter are small COG types, so I don't > > think they are the ones causing the microphonic sensitivity. > > I would try tapping the components with a plastic stick hit by a small > hammer while watching. > > > > I am thinking that a wire-wound inductor fully encased in epoxy > > would work better. > > Only if well shielded, to prevent EMI problems. > > It may work better simply because the leads are more flexible. > > > Joe > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/ > listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Re Technology. Was Naval Jelly
See lines prefaced by wh> below. Friday the 13th falls on Tuesday this week. Bill Hawkins -Original Message- From: J. Forster Sent: Tuesday, April 13, 2010 10:28 AM To: Mike Feher Cc: 'Discussion of precise time and frequency measurement' Subject: [time-nuts] OT: Re Technology. Was Naval Jelly In the '50s, WW II was not ancient history. We met people who had used weapons, explosives, and other things in war and knew the risks. The same is true, but in a much more limited way, after 'Nam. However, starting in the '60s, society regarded science as evil and it became political. wh> Science also became too complicated for a high-school education, so people found other things to get excited about, like Reality TV. More recently, science has been warped to support political agendas. wh> Politicians need lots of money to stay in politics, so many are owned by the very big businesses that support them. Science is warped by the interests of businesses that are too big to control. In a related way, cars, radios, TVs, and computers have "matured" to the point that even technically competant individuals can no longer modify or even repair them. (They still don't know if the Toyota failures are hardware, software, or a mix.) wh> You've heard of "fly by wire" as used by Airbus? Now we're getting "drive by wire" which replaces expensive mechanical linkages with sensors, computers, and actuators. There's no physical linkage from the accelerator to the carburetor, or the pedal to the brake hydraulic system. Worse, you can spend money on aircraft controls because the aircraft is so expensive, but car controls are as cheap as possible. We are all becomng hostages to the priesthood of so called "experts" in big government and the big corporations, and we really have little idea what is fact and what is politically motivated disinformation. wh> We could become a theocracy, but the leaders will be experts in the technology of manipulating people and their fears. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid
Sorry! -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Monday, April 12, 2010 10:07 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid boston On Mon, Apr 12, 2010 at 7:40 PM, Bill wrote: > Paul, do you live in Colorado or California? Most places in Texas where > chemicals are sold carry this kind of merchandize and one is free to buy > them...In quantity you may raise eyebrows but Texas is still a free > country! > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of paul swed > Sent: Monday, April 12, 2010 5:14 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid > > Thats some serious stuff. > I know a long time ago 30+ years you could buy all sorts of things for the > amateur chemist. > Especially if you lived in a farm region. > Its funny how things have changed. Everything is so dangerous these days. > I will say I needed sulphuric acid for a large battery set and after a big > run around I did finally find a auto store that sold a gallon for $2.50. > Three X more then I needed but what the heck. > But my goodness what type of store are you talking about. Thats some > serious > stuff depending on the concentration. > Regards > > On Mon, Apr 12, 2010 at 12:20 PM, Bill wrote: > > > I purchase 75% phosphoric acid at a commercial chemical > > establishment...They > > sell house cleaning chemicals for commercial cleaning folks. They sell > > sodium hydroxide (caustic soda) outstanding for etching aluminum outside > a > > closed space, nitric acid, sulphuric acid, hydrochloric acid, mek (methyl > > ethyl keytone), trichloroethylene (I think thats correct spelling), > > etcphosphoric will burn your hands but even at 75% it is not that > > caustic and putting hands in it momentarily to remove the object youre > > cleaning is NOT that bad with a little cold water hand rinse (and > > moisturizing crème as one weeney suggested), the damage is minimal and > > not > > generally lasting. Chemicals are easy to find especially in the city > and > > buying them over the internet might get you an inquiry from your local > DEA > > officer, Police department or sheriffs dept. I can state that with some > > degree of accuracy as I was an elected District/County attorney for > > approximately 14 years in Texas and had a close relationship with the > > authorities. > > > > > > > > W5STP > > > > > > > > -Original Message- > > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > > Behalf Of paul swed > > Sent: Monday, April 12, 2010 8:08 AM > > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid > > > > > > > > Well 8 oz fits my bill pretty well. > > > > Granted not 85% but from what I read on the thread I don't need that > > > > strength. > > > > Did look for jasco and did not see it. But it would be easy to overlook > > > > frankly. > > > > So many weird products > > > > > > > > On Mon, Apr 12, 2010 at 1:50 AM, Charles P. Steinmetz < > > > > charles_steinm...@lavabit.com> wrote: > > > > > > > > > Joe wrote: > > > > > > > > > > Where do you get [liquid phosphoric acid]? > > > > >> > > > > > > > > > > I buy concentrated (85% solution) phosphoric acid by the gallon on > eBay. > > > > > There are several good chemical suppliers selling that and other > useful > > > > > things. I've had good results with these folks, among others (although > I > > > > > dearly wish they'd switch from FedEx Ground to UPS): > > > > > > > > > > 250404008386 > > > > > > > > > > Best regards, > > > > > > > > > > Charles > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ___ > > > > > time-nuts mailing list -- time-nuts@febo.com > > > > > To unsubscribe, go to > > > > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > > > and follow the instructions there. > > > > > > > > > ___ > > > > time-nuts mailing list -- time-nuts@febo.com > > > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > > and follow the instructions there. > > > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@feb
Re: [time-nuts] Microphonic Inductor?
Hi there, I do have space on the PCB, but I am worried that the ceramic as well as ferrite cores both are sensitive to vibration. I will try Joe's idea of using a doorbell buzzer to introduce vibration. It's not easy to generate 1KHz vibration without professional (and heavy) equipment :) Another suggestion was to put the part on a scope, and lightly tap it, to see any variations in voltage. It's time to experiment. If anyone knows a good inductor-series (leaded or smt) that is known-insensitive to vibration please let us know! Thanks, Said In a message dated 4/13/2010 06:34:53 Pacific Daylight Time, wpxs...@gmail.com writes: Said, I assume you are using something like the Coilcraft 0603 LS series which seem to have ferrite cores. You might want to try a 0805 size part since that inductance is available in the CS series which are ceramic only. I don't know if size constraints prohibit using an 0805 but you can try one to see if the inductor is the problem.If you must use a 0603, you might try massaging the filter impedance so you can use a 390 nH which is available in 0603 size with a ceramic core. Then, you will either have to put up with a mismatch or include some impedance matching components. I use the LS series 0603s a lot and they are somewhat temperature sensitive if that could be an issue. The ceramic cored CS series don't seem to be temperature sensitive. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Microphonic Inductor?
Hi Most inductors are vibration sensitive from the windings moving relative to the core. If the part in question has windings you can get at - try gluing them down. Anything with some mass to it will do fine (RTV, hot melt glue, wax, what ever). The value will change, but if the vibe problem goes away you have useful data. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of saidj...@aol.com Sent: Tuesday, April 13, 2010 12:49 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Microphonic Inductor? Hi there, I do have space on the PCB, but I am worried that the ceramic as well as ferrite cores both are sensitive to vibration. I will try Joe's idea of using a doorbell buzzer to introduce vibration. It's not easy to generate 1KHz vibration without professional (and heavy) equipment :) Another suggestion was to put the part on a scope, and lightly tap it, to see any variations in voltage. It's time to experiment. If anyone knows a good inductor-series (leaded or smt) that is known-insensitive to vibration please let us know! Thanks, Said In a message dated 4/13/2010 06:34:53 Pacific Daylight Time, wpxs...@gmail.com writes: Said, I assume you are using something like the Coilcraft 0603 LS series which seem to have ferrite cores. You might want to try a 0805 size part since that inductance is available in the CS series which are ceramic only. I don't know if size constraints prohibit using an 0805 but you can try one to see if the inductor is the problem.If you must use a 0603, you might try massaging the filter impedance so you can use a 390 nH which is available in 0603 size with a ceramic core. Then, you will either have to put up with a mismatch or include some impedance matching components. I use the LS series 0603s a lot and they are somewhat temperature sensitive if that could be an issue. The ceramic cored CS series don't seem to be temperature sensitive. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] OT: Re Technology. Was Naval Jelly
Oh, yeah... there a lots of neat Prius hacks. Including conversion to plug-in hybrids with lithium batteries. For a good time see: http://priuschat.com/forums/prius-hybrid-news/51283-prius-a123-battery-fire-report.html BTW, Toyota sells a non-hybrid Prius overseas... it gets better milage than the hybrid... -- (I wonder if there's a hack to change the SOC limits?) Makes the warranty more impressive. _ The New Busy is not the too busy. Combine all your e-mail accounts with Hotmail. http://www.windowslive.com/campaign/thenewbusy?tile=multiaccount&ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_4 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Re Technology. Was Naval Jelly
Geeze..I was only trying to answer a question about phosphoric acid...how thoughtless of me not to be cognizant of the connection between phosphoric acid and politics/nanny state/etc. seems a bit tenuous but,I guess for some all existence is connected -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bill Hawkins Sent: Tuesday, April 13, 2010 11:36 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] OT: Re Technology. Was Naval Jelly See lines prefaced by wh> below. Friday the 13th falls on Tuesday this week. Bill Hawkins -Original Message- From: J. Forster Sent: Tuesday, April 13, 2010 10:28 AM To: Mike Feher Cc: 'Discussion of precise time and frequency measurement' Subject: [time-nuts] OT: Re Technology. Was Naval Jelly In the '50s, WW II was not ancient history. We met people who had used weapons, explosives, and other things in war and knew the risks. The same is true, but in a much more limited way, after 'Nam. However, starting in the '60s, society regarded science as evil and it became political. wh> Science also became too complicated for a high-school education, so people found other things to get excited about, like Reality TV. More recently, science has been warped to support political agendas. wh> Politicians need lots of money to stay in politics, so many are owned by the very big businesses that support them. Science is warped by the interests of businesses that are too big to control. In a related way, cars, radios, TVs, and computers have "matured" to the point that even technically competant individuals can no longer modify or even repair them. (They still don't know if the Toyota failures are hardware, software, or a mix.) wh> You've heard of "fly by wire" as used by Airbus? Now we're getting "drive by wire" which replaces expensive mechanical linkages with sensors, computers, and actuators. There's no physical linkage from the accelerator to the carburetor, or the pedal to the brake hydraulic system. Worse, you can spend money on aircraft controls because the aircraft is so expensive, but car controls are as cheap as possible. We are all becomng hostages to the priesthood of so called "experts" in big government and the big corporations, and we really have little idea what is fact and what is politically motivated disinformation. wh> We could become a theocracy, but the leaders will be experts in the technology of manipulating people and their fears. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] OT: Re Technology. Was Naval Jelly
Hi Mark: The Prius fire was caused by improper spacing. I've come across this in related areas. My son restored a 1941 D8 CAT and told me the lifters were hitting the valve cover. It turns out he substituted a gasket for the factory thick cork seal. The seal thickness was part of the design. In a similar fashion modern off road vehicles require the proper thickness of gaskets or things touch each other that are not supposed to. Have Fun, Brooke Clarke http://www.PRC68.com Mark Sims wrote: Oh, yeah... there a lots of neat Prius hacks. Including conversion to plug-in hybrids with lithium batteries. For a good time see: http://priuschat.com/forums/prius-hybrid-news/51283-prius-a123-battery-fire-report.html BTW, Toyota sells a non-hybrid Prius overseas... it gets better milage than the hybrid... -- (I wonder if there's a hack to change the SOC limits?) Makes the warranty more impressive. _ The New Busy is not the too busy. Combine all your e-mail accounts with Hotmail. http://www.windowslive.com/campaign/thenewbusy?tile=multiaccount&ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_4 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Microphonic Inductor?
Said, time-nuts-boun...@febo.com wrote on 04/13/2010 12:49:05 PM: > From: > > saidj...@aol.com > > To: > > time-nuts@febo.com > > Date: > > 04/13/2010 12:54 PM > > Subject: > > Re: [time-nuts] Microphonic Inductor? > > Sent by: > > time-nuts-boun...@febo.com > > Hi there, > > I do have space on the PCB, but I am worried that the ceramic > as well as ferrite cores both are sensitive to vibration. > > I will try Joe's idea of using a doorbell buzzer to introduce > vibration. > It's not easy to generate 1KHz vibration without professional > (and heavy) equipment :) > > Another suggestion was to put the part on a scope, and lightly > tap it, to see any variations in voltage. > > It's time to experiment. > > If anyone knows a good inductor-series (leaded or smt) that is > known-insensitive to vibration please let us know! Air wound coil potted in wax. Or soft epoxy. You can make your own, if it comes to that. Joe > Thanks, > Said > > > In a message dated 4/13/2010 06:34:53 Pacific Daylight Time, > wpxs...@gmail.com writes: > > Said, > I assume you are using something like the Coilcraft 0603 LS series which > seem to have ferrite cores. You might want to try a 0805 size part since > that inductance is available in the CS series which are ceramic only. I > don't know if size constraints prohibit using an 0805 but you > can try one > to > see if the inductor is the problem.If you must use a 0603, you might try > massaging the filter impedance so you can use a 390 nH which isavailable > in > 0603 size with a ceramic core. Then, you will either have to > put up with a > mismatch or include some impedance matching components. I use > the LS series > 0603s a lot and they are somewhat temperature sensitive if > that could be an > issue. The ceramic cored CS series don't seem to be > temperature sensitive. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/ > listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Microphonic Inductor?
In message , Joseph M Gwinn writes: >> If anyone knows a good inductor-series (leaded or smt) that is >> known-insensitive to vibration please let us know! > >Air wound coil potted in wax. Or soft epoxy. You can make your own, if >it comes to that. Be aware that all non-closed coils are microfonic relative to the earths magnetic field, and there is nothing you you can do about it, but a closed design (toroid) or a mu-metal shield. This is more pronounced for cored coils than air-coils, because all core materials has magnetic hysteresis. The effect is usually ignored, but I wouldn't be surprised if it showed up for time-nuts... Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] repairing Maser threads
Hi, It does not seem Time-Nutty but I need help repairing threads in a mounting hole. I recently installed a new ion pump in an EFOS2 Hydrogen maser and two of the mounting holes (metric M5) have damaged threads. The bolts go in fine but wont tighten and if you wiggle the bolt you can pull it out. I've looked at the various locktight and permatex stuff but am unsure that they will do what I want. I'm hoping someone has experience with these and can advise me. What I hope will happen with the right product is that I apply it to the threads, screw in the bolt until it just contacts the lock washer, wait until the goop cures, and then tighten until the lock washer is compressed and the bolt is tight. Just don't know what product to try! Want to be able to disassemble without special tools or heating. Any help is appreciated! Corby Dawson Gains 625% from Killer Penny Stocks! Sign up for FREE alerts on the next Killer Stock. http://thirdpartyoffers.juno.com/TGL3141/4bc4b2233fb333a8aem04duc ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] repairing Maser threads
The best solution is Heli-Coils (or equal). They are even used in aircraft and spacecraft. They do require special, oversized taps and install tools, but are, IMO, the only way to go. Search eBay and contact the sellers if they don't list your size. Best, -John = > Hi, > > It does not seem Time-Nutty but I need help repairing threads in a > mounting hole. > > I recently installed a new ion pump in an EFOS2 Hydrogen maser and two of > the mounting holes (metric M5) > > have damaged threads. > > The bolts go in fine but wont tighten and if you wiggle the bolt you can > pull it out. > > I've looked at the various locktight and permatex stuff but am unsure > that they will do what I want. > > I'm hoping someone has experience with these and can advise me. > > What I hope will happen with the right product is that I apply it to the > threads, screw in the bolt until it just contacts the lock washer, wait > until the goop cures, and then > > tighten until the lock washer is compressed and the bolt is tight. > > Just don't know what product to try! Want to be able to disassemble > without special tools or heating. > > Any help is appreciated! > > Corby Dawson > > Gains 625% from Killer Penny Stocks! > Sign up for FREE alerts on the next Killer Stock. > http://thirdpartyoffers.juno.com/TGL3141/4bc4b2233fb333a8aem04duc > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Microphonic Inductor?
True enough, but don't forget that a shaker table is a big moving electromagnet right next to the device under test. I would think that the shaker's field would dominate any such errors, especially for larger tables running in random vibration or pulse modes. Cheers, Neil www.gruending.net On Tue, Apr 13, 2010 at 10:57 AM, Poul-Henning Kamp wrote: > In message > y.com>, Joseph M Gwinn writes: > >>> If anyone knows a good inductor-series (leaded or smt) that is >>> known-insensitive to vibration please let us know! >> >>Air wound coil potted in wax. Or soft epoxy. You can make your own, if >>it comes to that. > > Be aware that all non-closed coils are microfonic relative to the > earths magnetic field, and there is nothing you you can do about > it, but a closed design (toroid) or a mu-metal shield. > > This is more pronounced for cored coils than air-coils, because all > core materials has magnetic hysteresis. > > The effect is usually ignored, but I wouldn't be surprised if it > showed up for time-nuts... > > Poul-Henning > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] repairing Maser threads
Corby wrote: What I hope will happen with the right product is that I apply it to the threads, screw in the bolt until it just contacts the lock washer, wait until the goop cures, and then tighten until the lock washer is compressed and the bolt is tight. Just don't know what product to try! Want to be able to disassemble without special tools or heating. Tall order. John already suggested helicoils, which are probably the best option. To avoid messing with the chassis, you could turn some custom bolts that are slightly larger but with the same pitch (the standard pitch for M5 is 0.8 mm, so you'd make some "M5.2 x 0.8" or "M5.5 x 0.8" bolts). I have had success in emergencies by getting the female threads surgically clean, then using metal-filled epoxy to fill up the threads and, after hardening, running a tap down them (leave several threads at the entrance unfilled, to get the tap started in synch with the originals). But I don't consider this a proper repair and have always re-tapped for helicoils at the earliest opportunity. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Microphonic Inductor?
That is a big concern of ours of course! It's a massive voice coil in the shaker.. bye, Said In a message dated 4/13/2010 11:20:16 Pacific Daylight Time, n...@gruending.net writes: True enough, but don't forget that a shaker table is a big moving electromagnet right next to the device under test. I would think that the shaker's field would dominate any such errors, especially for larger tables running in random vibration or pulse modes. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] repairing Maser threads
Hi Corby, I don't have experience with the ion pump you mention but have repaired several rotators (aluminium casting) where the threads have become very worn or stripped using a product called recoil. These are manufactured in Australia but available around the world. You drill out the drill specified for the size kit you are using and then tap the hole with the tap provided in the kit. Once the hole is ready you insert the 'Recoil' using the special tool provided and then break off and remove the tang following the instructions. Result - a threaded hole probably stronger than the original. These may also be known as Helicoils. There is another method that uses a special solder but that requires heating the object up to the temperature needed to melt the solder and may not be suitable for what you want. Good Luck with the repair Regards Malcolm ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] repairing Maser threads
Howdy Corby - just a couple of thoughts. I grew up in a machine shop and am an aircraft mechanic. If you haven't used them before, Helicoils require a larger hole to be drilled and tapped, because you basically install a large threaded spacer into the original location with the right size inside threads for your original screw. It takes a somewhat expensive drill & special tap and insert tool to complete. Another solution - especially with metric - is to tap the holes ( only bad - or all - so that they all match) to the next larger Metric size - of the same thread pitch as original - so as not to cut across the original threads, but just cut the same thread pitch to the next size, such as from 5mm to 5.5mm or 6mm. Then you only have to buy a standard - not too expesive - metric tap - and some new slightly larger hardware. You can also consider tapping the original holes to the next larger SAE - probably National Fine thread - but your new threads will cut across the original threads slightly. It really depends on how much room you have to do the work - and how much strength you need - Hope this helps Dave Powers - KA0KCI From: Corby Dawson To: time-nuts@febo.com Sent: Tue, April 13, 2010 1:03:55 PM Subject: [time-nuts] repairing Maser threads Hi, It does not seem Time-Nutty but I need help repairing threads in a mounting hole. I recently installed a new ion pump in an EFOS2 Hydrogen maser and two of the mounting holes (metric M5) have damaged threads. The bolts go in fine but wont tighten and if you wiggle the bolt you can pull it out. I've looked at the various locktight and permatex stuff but am unsure that they will do what I want. I'm hoping someone has experience with these and can advise me. What I hope will happen with the right product is that I apply it to the threads, screw in the bolt until it just contacts the lock washer, wait until the goop cures, and then tighten until the lock washer is compressed and the bolt is tight. Just don't know what product to try! Want to be able to disassemble without special tools or heating. Any help is appreciated! Corby Dawson Gains 625% from Killer Penny Stocks! Sign up for FREE alerts on the next Killer Stock. http://thirdpartyoffers.juno.com/TGL3141/4bc4b2233fb333a8aem04duc ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid
Not sure I want to be on the DHS list with this thread. But the fact is we learned. We learned how to handle things that were dangerous be it tractors, voltage or chemicals. Today well its said here. Footze ball, yahoo! On Tue, Apr 13, 2010 at 12:46 PM, Bill wrote: > Sorry! > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of paul swed > Sent: Monday, April 12, 2010 10:07 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid > > boston > > On Mon, Apr 12, 2010 at 7:40 PM, Bill wrote: > > > Paul, do you live in Colorado or California? Most places in Texas where > > chemicals are sold carry this kind of merchandize and one is free to buy > > them...In quantity you may raise eyebrows but Texas is still a free > > country! > > > > -Original Message- > > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > > Behalf Of paul swed > > Sent: Monday, April 12, 2010 5:14 PM > > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid > > > > Thats some serious stuff. > > I know a long time ago 30+ years you could buy all sorts of things for > the > > amateur chemist. > > Especially if you lived in a farm region. > > Its funny how things have changed. Everything is so dangerous these days. > > I will say I needed sulphuric acid for a large battery set and after a > big > > run around I did finally find a auto store that sold a gallon for $2.50. > > Three X more then I needed but what the heck. > > But my goodness what type of store are you talking about. Thats some > > serious > > stuff depending on the concentration. > > Regards > > > > On Mon, Apr 12, 2010 at 12:20 PM, Bill wrote: > > > > > I purchase 75% phosphoric acid at a commercial chemical > > > establishment...They > > > sell house cleaning chemicals for commercial cleaning folks. They sell > > > sodium hydroxide (caustic soda) outstanding for etching aluminum > outside > > a > > > closed space, nitric acid, sulphuric acid, hydrochloric acid, mek > (methyl > > > ethyl keytone), trichloroethylene (I think that’s correct spelling), > > > etcphosphoric will burn your hands but even at 75% it is not that > > > caustic and putting hands in it momentarily to remove the object you’re > > > cleaning is NOT that bad…with a little cold water hand rinse (and > > > moisturizing crème as one ‘weeney’ suggested), the damage is minimal > and > > > not > > > generally lasting. Chemicals are easy to find especially in the city > > and > > > buying them over the internet might get you an inquiry from your local > > DEA > > > officer, Police department or sheriff’s dept. I can state that with > some > > > degree of accuracy as I was an elected District/County attorney for > > > approximately 14 years in Texas and had a ‘close’ relationship with the > > > ‘authorities.’ > > > > > > > > > > > > W5STP > > > > > > > > > > > > -Original Message- > > > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] > On > > > Behalf Of paul swed > > > Sent: Monday, April 12, 2010 8:08 AM > > > To: Discussion of precise time and frequency measurement > > > Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric > acid > > > > > > > > > > > > Well 8 oz fits my bill pretty well. > > > > > > Granted not 85% but from what I read on the thread I don't need that > > > > > > strength. > > > > > > Did look for jasco and did not see it. But it would be easy to overlook > > > > > > frankly. > > > > > > So many weird products > > > > > > > > > > > > On Mon, Apr 12, 2010 at 1:50 AM, Charles P. Steinmetz < > > > > > > charles_steinm...@lavabit.com> wrote: > > > > > > > > > > > > > Joe wrote: > > > > > > > > > > > > > > Where do you get [liquid phosphoric acid]? > > > > > > >> > > > > > > > > > > > > > > I buy concentrated (85% solution) phosphoric acid by the gallon on > > eBay. > > > > > > > There are several good chemical suppliers selling that and other > > useful > > > > > > > things. I've had good results with these folks, among others > (although > > I > > > > > > > dearly wish they'd switch from FedEx Ground to UPS): > > > > > > > > > > > > > > 250404008386 > > > > > > > > > > > > > > Best regards, > > > > > > > > > > > > > > Charles > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ___ > > > > > > > time-nuts mailing list -- time-nuts@febo.com > > > > > > > To unsubscribe, go to > > > > > > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > > > > > and follow the instructions there. > > > > > > > > > > > > > ___ > > > > > > time-nuts mailing list -- time-nuts@febo.com > > > > > > To unsubscribe, go to > > > https://www.febo.com/cgi-bin/mailman/l
Re: [time-nuts] repairing Maser threads
Without having had the benefit of seeing what you're working with, this would be the way I'd lean as well. -ls- Dave Powers wrote: > Howdy Corby - > > just a couple of thoughts. I grew up in a machine shop and am an > aircraft mechanic. > > If you haven't used them before, Helicoils require a larger hole to be > drilled and tapped, because you basically install a large threaded > spacer into the original location with the right size inside threads > for your original screw. It takes a somewhat expensive drill & special > tap and insert tool to complete. > > Another solution - especially with metric - is to tap the holes ( only > bad - or all - so that they all match) to the next larger Metric size > - of the same thread pitch as original - so as not to cut across the > original threads, but just cut the same thread pitch to the > next size, such as from 5mm to 5.5mm or 6mm. Then you only have to buy > a standard - not too expesive - metric tap - and some new slightly > larger hardware. > > You can also consider tapping the original holes to the next larger > SAE - probably National Fine thread - but your new threads will cut > across the original threads slightly. > > It really depends on how much room you have to do the work - and how > much strength you need - > > Hope this helps > > Dave Powers - KA0KCI > > > > > > > > From: Corby Dawson > To: time-nuts@febo.com > Sent: Tue, April 13, 2010 1:03:55 PM > Subject: [time-nuts] repairing Maser threads > > Hi, > > It does not seem Time-Nutty but I need help repairing threads in a > mounting hole. > > I recently installed a new ion pump in an EFOS2 Hydrogen maser and two > of > the mounting holes (metric M5) > > have damaged threads. > > The bolts go in fine but wont tighten and if you wiggle the bolt you > can > pull it out. > > I've looked at the various locktight and permatex stuff but am unsure > that they will do what I want. > > I'm hoping someone has experience with these and can advise me. > > What I hope will happen with the right product is that I apply it to > the > threads, screw in the bolt until it just contacts the lock washer, > wait > until the goop cures, and then > > tighten until the lock washer is compressed and the bolt is tight. > > Just don't know what product to try! Want to be able to disassemble > without special tools or heating. > > Any help is appreciated! > > Corby Dawson > > Gains 625% from Killer Penny Stocks! > Sign up for FREE alerts on the next Killer Stock. > http://thirdpartyoffers.juno.com/TGL3141/4bc4b2233fb333a8aem04duc > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid
yeah! back to the real thread! more interesting and for dummies like me, more informative. -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Tuesday, April 13, 2010 2:18 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid Not sure I want to be on the DHS list with this thread. But the fact is we learned. We learned how to handle things that were dangerous be it tractors, voltage or chemicals. Today well its said here. Footze ball, yahoo! On Tue, Apr 13, 2010 at 12:46 PM, Bill wrote: > Sorry! > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of paul swed > Sent: Monday, April 12, 2010 10:07 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid > > boston > > On Mon, Apr 12, 2010 at 7:40 PM, Bill wrote: > > > Paul, do you live in Colorado or California? Most places in Texas where > > chemicals are sold carry this kind of merchandize and one is free to buy > > them...In quantity you may raise eyebrows but Texas is still a free > > country! > > > > -Original Message- > > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > > Behalf Of paul swed > > Sent: Monday, April 12, 2010 5:14 PM > > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid > > > > Thats some serious stuff. > > I know a long time ago 30+ years you could buy all sorts of things for > the > > amateur chemist. > > Especially if you lived in a farm region. > > Its funny how things have changed. Everything is so dangerous these days. > > I will say I needed sulphuric acid for a large battery set and after a > big > > run around I did finally find a auto store that sold a gallon for $2.50. > > Three X more then I needed but what the heck. > > But my goodness what type of store are you talking about. Thats some > > serious > > stuff depending on the concentration. > > Regards > > > > On Mon, Apr 12, 2010 at 12:20 PM, Bill wrote: > > > > > I purchase 75% phosphoric acid at a commercial chemical > > > establishment...They > > > sell house cleaning chemicals for commercial cleaning folks. They sell > > > sodium hydroxide (caustic soda) outstanding for etching aluminum > outside > > a > > > closed space, nitric acid, sulphuric acid, hydrochloric acid, mek > (methyl > > > ethyl keytone), trichloroethylene (I think thats correct spelling), > > > etcphosphoric will burn your hands but even at 75% it is not that > > > caustic and putting hands in it momentarily to remove the object youre > > > cleaning is NOT that bad with a little cold water hand rinse (and > > > moisturizing crème as one weeney suggested), the damage is minimal > and > > > not > > > generally lasting. Chemicals are easy to find especially in the city > > and > > > buying them over the internet might get you an inquiry from your local > > DEA > > > officer, Police department or sheriffs dept. I can state that with > some > > > degree of accuracy as I was an elected District/County attorney for > > > approximately 14 years in Texas and had a close relationship with the > > > authorities. > > > > > > > > > > > > W5STP > > > > > > > > > > > > -Original Message- > > > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] > On > > > Behalf Of paul swed > > > Sent: Monday, April 12, 2010 8:08 AM > > > To: Discussion of precise time and frequency measurement > > > Subject: Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric > acid > > > > > > > > > > > > Well 8 oz fits my bill pretty well. > > > > > > Granted not 85% but from what I read on the thread I don't need that > > > > > > strength. > > > > > > Did look for jasco and did not see it. But it would be easy to overlook > > > > > > frankly. > > > > > > So many weird products > > > > > > > > > > > > On Mon, Apr 12, 2010 at 1:50 AM, Charles P. Steinmetz < > > > > > > charles_steinm...@lavabit.com> wrote: > > > > > > > > > > > > > Joe wrote: > > > > > > > > > > > > > > Where do you get [liquid phosphoric acid]? > > > > > > >> > > > > > > > > > > > > > > I buy concentrated (85% solution) phosphoric acid by the gallon on > > eBay. > > > > > > > There are several good chemical suppliers selling that and other > > useful > > > > > > > things. I've had good results with these folks, among others > (although > > I > > > > > > > dearly wish they'd switch from FedEx Ground to UPS): > > > > > > > > > > > > > > 250404008386 > > > > > > > > > > > > > > Best regards, > > > > > > > > > > > > > > Charles > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ___ > > > > > > > time-nuts mailing list -- ti
Re: [time-nuts] repairing Maser threads
Take a look at You-Tube "How to Repair Threads with a Heli-Coil Insert" ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] repairing Maser threads
Depending on the stress on the screw and how badly it's stripped, I would consider some Loctite; especially if you only need to do it once. Otherwise, Dave and Larry have it quite right. Don Larry Snyder > Without having had the benefit of seeing what you're working with, > this would be the way I'd lean as well. > -ls- > > > > Dave Powers wrote: >> Howdy Corby - >> >> just a couple of thoughts. I grew up in a machine shop and am an >> aircraft mechanic. >> >> If you haven't used them before, Helicoils require a larger hole to be >> drilled and tapped, because you basically install a large threaded >> spacer into the original location with the right size inside threads >> for your original screw. It takes a somewhat expensive drill & special >> tap and insert tool to complete. >> >> Another solution - especially with metric - is to tap the holes ( only >> bad - or all - so that they all match) to the next larger Metric size >> - of the same thread pitch as original - so as not to cut across the >> original threads, but just cut the same thread pitch to the >> next size, such as from 5mm to 5.5mm or 6mm. Then you only have to buy >> a standard - not too expesive - metric tap - and some new slightly >> larger hardware. >> >> You can also consider tapping the original holes to the next larger >> SAE - probably National Fine thread - but your new threads will cut >> across the original threads slightly. >> >> It really depends on how much room you have to do the work - and how >> much strength you need - >> >> Hope this helps >> >> Dave Powers - KA0KCI >> >> >> >> >> >> >> >> From: Corby Dawson >> To: time-nuts@febo.com >> Sent: Tue, April 13, 2010 1:03:55 PM >> Subject: [time-nuts] repairing Maser threads >> >> Hi, >> >> It does not seem Time-Nutty but I need help repairing threads in a >> mounting hole. >> >> I recently installed a new ion pump in an EFOS2 Hydrogen maser and two >> of >> the mounting holes (metric M5) >> >> have damaged threads. >> >> The bolts go in fine but wont tighten and if you wiggle the bolt you >> can >> pull it out. >> >> I've looked at the various locktight and permatex stuff but am unsure >> that they will do what I want. >> >> I'm hoping someone has experience with these and can advise me. >> >> What I hope will happen with the right product is that I apply it to >> the >> threads, screw in the bolt until it just contacts the lock washer, >> wait >> until the goop cures, and then >> >> tighten until the lock washer is compressed and the bolt is tight. >> >> Just don't know what product to try! Want to be able to disassemble >> without special tools or heating. >> >> Any help is appreciated! >> >> Corby Dawson >> >> Gains 625% from Killer Penny Stocks! >> Sign up for FREE alerts on the next Killer Stock. >> http://thirdpartyoffers.juno.com/TGL3141/4bc4b2233fb333a8aem04duc >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. -- Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] repairing Maser threads
cdel...@juno.com said: > I recently installed a new ion pump in an EFOS2 Hydrogen maser and two of > the mounting holes (metric M5) have damaged threads. > The bolts go in fine but wont tighten and if you wiggle the bolt you can > pull it out. That sounds fishy. Do the holes look chewed up? Did somebody strip the threads? Are you using the right size bolt? Can you get a nut on the back side of the hole? -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] repairing Maser threads
Doesn't sound fishy at all to me. But I have much experience stripping threads. It is easy, just make it snug,then a "bit tighter". Or, the threads could have been damaged by the original installer. That happens too (just not as often). If the fit was a bit on the loose side initially, it could look like a lot of the thread remains. With little stress or vibration, it could remain happily in place for some time. Of course, installing the wrong diameter screw with the correct pitch could do the same. At 04:15 PM 4/13/2010, Hal Murray wrote: cdel...@juno.com said: > I recently installed a new ion pump in an EFOS2 Hydrogen maser and two of > the mounting holes (metric M5) have damaged threads. > The bolts go in fine but wont tighten and if you wiggle the bolt you can > pull it out. That sounds fishy. Do the holes look chewed up? Did somebody strip the threads? Are you using the right size bolt? Can you get a nut on the back side of the hole? -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.437 / Virus Database: 271.1.1/2808 - Release Date: 04/13/10 06:32:00 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] repairing Maser threads
If Corby is installing an ion pump, I suspect the bolts are on something like a Conflat flange which requires a fair amount of torque to compress the metal gasket and seal right. The bolts could well have been stripped out trying to fix a leaking seal. Nuts would work, if the holes go through. Helicoils can be used on blind or through holes. For blind holes you need a bottoming Helicoil tap. -J0hn === > > cdel...@juno.com said: >> I recently installed a new ion pump in an EFOS2 Hydrogen maser and two >> of >> the mounting holes (metric M5) have damaged threads. > >> The bolts go in fine but wont tighten and if you wiggle the bolt you can >> pull it out. > > That sounds fishy. > > Do the holes look chewed up? Did somebody strip the threads? > > Are you using the right size bolt? > > Can you get a nut on the back side of the hole? > > > > -- > These are my opinions, not necessarily my employer's. I hate spam. > > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] repairing Maser threads
Dave wrote: Another solution - especially with metric - is to tap the holes ( only bad - or all - so that they all match) to the next larger Metric size - of the same thread pitch as original - so as not to cut across the original threads, but just cut the same thread pitch to the next size, such as from 5mm to 5.5mm or 6mm. Then you only have to buy a standard - not too expesive - metric tap - and some new slightly larger hardware. Unfortunately, 5 mm is the only standard metric thread with a 0.8 mm pitch, so you'd need a custom tap and would need to make custom bolts. Hence, my suggestion to just make some custom bolts in "M5.2x0.8" or "M5.5x0.8," whatever is necessary to get a tight fit. Same approach, but less work (although if someone ever loses the bolts, they'll go crazy trying to figure out what to use for replacements). What I didn't mention previously, but would be good practice if you went that way, is to cut one straight flute on the bolts (look at a self-tapping machine screw to get the idea) to make it easier for them to deepen the major diameter of the original 5 mm thread. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] repairing Maser threads
Hi, you can not go step like 5.5 mm or so the best thing is to cut a new M6 thread because it is the next most available screw size in metric. I had a lot of problem with the American size thread but the best solution was always the next higher most common metric size.. Rgds Ernie. -Original Message- From: Charles P. Steinmetz To: Discussion of precise time and frequency measurement Sent: Wed, Apr 14, 2010 12:19 am Subject: Re: [time-nuts] repairing Maser threads Dave wrote: >Another solution - especially with metric - is to tap the holes ( >only bad - >or all - so that they all match) to the next larger >Metric size - of the same >thread pitch as original - so as not to >cut across the original threads, but >just cut the same thread pitch >to the next size, such as from 5mm to 5.5mm or >6mm. Then you only >have to buy a standard - not too expesive - metric tap - >and some >new slightly larger hardware. Unfortunately, 5 mm is the only standard metric thread with a 0.8 mm pitch, so you'd need a custom tap and would need to make custom bolts. Hence, my suggestion to just make some custom bolts in "M5.2x0.8" or "M5.5x0.8," whatever is necessary to get a tight fit. Same approach, but less work (although if someone ever loses the bolts, they'll go crazy trying to figure out what to use for replacements). What I didn't mention previously, but would be good practice if you went that way, is to cut one straight flute on the bolts (look at a self-tapping machine screw to get the idea) to make it easier for them to deepen the major diameter of the original 5 mm thread. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. = ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] repairing Maser threads
I am just getting home and have read all the replies so far. Have you tried just replacing the bolts? New bolts with new threads with old hole and old threads may work better than the old bolts with old threads. It won't be perfect but might get you by. Another option along the helicoil line is to bore a larger hole, tap it with whatever, get a piece of tubing of the appropriate material and thickness, tap the external surface to match your larger hole and thread and tap the inside surface with the M5x0.8 thread. Make a 'slot' in the end so you can insert and remove with a screw driver. This all depends on what the size, shape, thickness, etc., you have to work with. Good luck. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Corby Dawson Sent: Tuesday, April 13, 2010 1:04 PM To: time-nuts@febo.com Subject: [time-nuts] repairing Maser threads Hi, It does not seem Time-Nutty but I need help repairing threads in a mounting hole. I recently installed a new ion pump in an EFOS2 Hydrogen maser and two of the mounting holes (metric M5) have damaged threads. The bolts go in fine but wont tighten and if you wiggle the bolt you can pull it out. I've looked at the various locktight and permatex stuff but am unsure that they will do what I want. I'm hoping someone has experience with these and can advise me. What I hope will happen with the right product is that I apply it to the threads, screw in the bolt until it just contacts the lock washer, wait until the goop cures, and then tighten until the lock washer is compressed and the bolt is tight. Just don't know what product to try! Want to be able to disassemble without special tools or heating. Any help is appreciated! Corby Dawson Gains 625% from Killer Penny Stocks! Sign up for FREE alerts on the next Killer Stock. http://thirdpartyoffers.juno.com/TGL3141/4bc4b2233fb333a8aem04duc ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
